cleaning viewfinder in a 300D

My son just got a used 300D and there are black spots and fuz in the viewfinder...is there anyway to clean it? I took the lens off and looked inside the camera and the spots are on the top mirror......what is the best thing to use to get the stuff off?
thanks,
Kim

Ummm, by "top mirror" do you mean the main mirror (not the submirror underneath)?

Or are you looking at the bottom side of the focusing screen?

Anything that's sharp in the viewfinder is on the focusing screen, not the mirror.

In either case, first cleaning effort should be with a handheld blower. The Rocket Blower is the best one...

-js

Its annoying as i have the same problem with my 400D but has no effect on the pictures taken so i have just learnt to live with it as i have heard that you dont want to disturb the focusing screen.
Itried a rocket blower with no luck.

I've had the same problems. Gentle puffs with a rocket blower worked for me, and removed the debris.